Selective polyurethane prepolymer synthesis

Polyurethane prepolymers obtainable by a reaction of

• I. at least one isocyanate-containing compound having a molecular weight of 120 Da to 1000 Da with
• II. a hydroxy-functionalized polymer having a number-average molecular weight Mn of 3500 to 100000 Da,
• in the presence of a catalyst, characterized in that the molecular weight profile, measured by gel permeation chromatography, of the polyurethane prepolymers from 2000 Da (x1) to 200000 Da (x3) along the x-axis has a first section with an area integral FI and a second section with an area integral FII, for which the ratio FII/FI is between 0 up to and including 0.4, where the first section extends from x1 to x2 and the second section extends from x2 to x3, and x2 defines the extreme point between the last intensity maximum (M1a) in the first section, situated in the region of the molecular weight of the hydroxy-functionalized polymer, and the subsequent intensity maximum (M2) in the second section.